Please understand that I am not asking what are the things that make us scream. I mean... why scream? Why would this particular reaction evolve to be our response to things which are frightening? It's almost as if evolution has kindly gifted us with a response that says, "Oh, by the way scary lion/tiger/bear/monster. Just in case you didn't notice me and you might be hungry, here is an extremely easy to follow audio indicator as to my exact location for your nomming pleasure. And by the time you get to me I promise to be succulently basted in my own urine." If I were designing a creature for a fantasy or science fiction world, these particular responses are not what I would choose in the design of my creatures. They don't seem very intuitive. So, why would evolution do this?
That's a pretty good question. I think both Rumpole and Xeno are at least partly right. I know that, for instance, if my boyfriend is tickling me, I scream in hopes that he'll either stop or someone else will make him stop. I think that, also, screaming (or, if you want to be fancy, vociferation) might be a form of stress release. I mean, if you're stressed out and wound up, you're more prone to be nervous or jumpy, and therefore probably more likely to scream if you are startled. I also think about a study I read about people who listen to metal/hardcore music tending to be more mellow. And what do metal musicians do? They scream. I know that if I have a tough day, nothing relaxes me more than turning on some music in my car and belting it out until my voice is hoarse. I don't know much about the subject, so this is just freestyle speculation.
Partly, I believe it is a way of summoning others of the "tribe" for assistance. But it may also serve to attempt to frighten off a predator. The adrenaline surge heighten's awareness and prepares for the fight or flight response. The scream flushes out the lungs, and is followed by a deep, oxygenating breath. I also wonder if screaming helps focus the strength and attention of the person feeling threatened, such as the Ki-ya in martial arts.
This one did come to mind for me as well. Nature's mistakes don't make it in the game of passing on genes, so there must be an advantage to an autonomic response which is sufficient to offset the fact that a predator's attention has now been unequivocally drawn. As for the scream being a tool to bring the rest of the pack in for support. Perhaps. It is known that certain primates have particular calls for different kinds of dangers. Although they do not possess the syntax to cry out, "Holy crap! Did you see the size of that leopard that almost ate Krug?" they can scream out their equivalent of LEOPARD! to the rest of the troop, giving the troop enough information to act appropriately to the given threat. But human screams do not contain this kind of information.
Don't they? On at least a subconscious level hearing someone scream usually invokes fear in everyone around the screamer.
I agree with the stress release idea. You're in a scary situation, you're afraid, the tension is building up inside you...and then you scream, and you feel a little more relaxed. At least, that's what happens to me when I'm on a roller coaster.
I've been told that it's because of ice cream. Scientifically though, I dont think I can add anymore information --I feel it's all likely been covered. But I can elaborate. It's an instinctive, defensive reaction used to summon help and disorient attackers. While we may not be able communicate with our screams, emotion travels. A scared scream versus a cry of joy is usually distinguishable. A scream will also elevate blood pressure and number of heartbeats per minute. To be super scientific, I actually looked this up from my old anatomy and physiology text, and this is the gist I got: When the message for fear hits the spinal chord via the neurons, we feel a sense of fear which, thanks to our adrenocortocotropic gland (took me four tries to spell that right ), adrenaline is produced to, like Cogito said, prepare for a fight or flight. I found the teeth thing interesting. I wonder if that's an added benefit or if that might have had something to do with the purpose of why we scream. Interesting thread, Wrey.
I'd like to be able to contribute intelligently to this thread, but the second I saw the title all I could think was for ice cream. *sigh* :redface: Edit: Nevermind - I was beaten to the punch, lol.
Are we sure it's a reflexive response and not a conditioned one? For me at least, the normal response is for my diaphram to sieze up and prevent me from screaming. About the only exception is if I unexpectedly stumble and let out a "woah," and even that only happens about half the time.
Conversely, I've found that the only time I can scream is when I'm scared. If I try to fake scream, I can't do it. It's just a little squeak.
Good point. Even if you CAN produce a scream when you aren't scared, does it have the same power behind it? It says something about the setup and physiological state prior to the actual scream.
good question... but not everyone screams when frightened... some just gasp, and/or stand paralyzed and silent... so a further question [or a more specific one] might be why do some people scream in fear?
Sounds psychological to me, though I dont actually have evidence to uphold my claim this time. Like how some people might choose to fight and some might opt for flight, maybe it makes more sense to some to be as quiet as they can be-- Maybe some feel it makes sense to be quieter in hopes of not drawing more attackers, particularly in humans prone to choose fight over flight? You certainly wouldnt want more attackers to find you if you choose to stay, after all. Or it could just be a "survival of the fittest" thing. The giraffe with the longer neck wins --and the human who screams loudest wins? Or, it could be that the fact that many people remain quiet when threatened is a later developed trait? After verbal language became prominent, perhaps many found that a scream to alert the tribe was no longer necessary, and instead communicated with words? I'm not sure about this last idea, though logically it makes the most sense to me. Language is a relatively new tool we use --could we have evolved that quickly for many humans to change their reactions to fear?
What about that gasp? Is that an interrupted scream? The first step in screaming is a deep inhalation. Clearly, some situations are better served by concealment, or at least avoiding notice. I think that is the basis of the freeze response. Scream AND freeze is an odd reaction, but not uncommon. It doesn't seem well adapted for survival, but it could be an overlap of warring reactions to a threat.
I just gasped, actually (my dog caught me off guard :redface: ), and I do think that's probably an interrupted scream, although my scream was interrupted, I think, because I realized the threat was in fact not a threat. My heart's still beating pretty fast though --so that strengthens my idea that is an interrupted scream; I still felt the adrenaline surge, so the brain sending "FEAR" to my spinal chord did happen, I'd imagine, but I stopped my scream because I realized before I screamed that it wasnt a threat. So maybe, those who dont scream, dont scream because they learned that the perceived threat was actually harmless? Perhaps it's not evolutionary or inborn at all (those who interrupt their screams, I mean), but a habit? I know that I perceive threats more times than there actually are threats. Is it possible that non-screamers dont scream out of habit? To slightly redirect the conversation, can I ask, Why do we cry? Screaming makes sense to me psycho- and physiologically, but what about feeling hurt or upset or violated makes us leak bodily fluids? That doesnt make sense to me. When I cry, my nose starts running and my tear ducts react --but why is that? Mucus and tear ducts are essentially defense mechanisms against bacteria and viruses... but emotional pain is not a virus. Hmm...
When you cry, your tear ducts expel excess hormones from your body (essentially, the bad emotion) in your tears, and because your tear ducts and your nostrils are close together, sometimes the tears end up in your nose too. That's why your tears taste different when you're crying to when you have something in your eye.
Oh, so there went my super-scientific question. I've never tasted my "have something in my eye" tears, but the sad tears taste extremely salty. Hmm, now I want to poke myself in the eye to see what those tears taste like, heehee. Thank you, friend. And PS: Your avatar rocks. I still havent gotten around to making mine..
I guess it's the combination of trying to imtimidate the threat, summoning help and relieving the feelings.
I never scream to be honest with you. But for the people that do, you are some scared sons of B's. In all seriousness though, I usually just face my fear and try to get through to whatever has put that fear in me that I am in fact the boss here. I'm seriously not scared of anything now that I think about it. I think the only thing that actually gets my blood pumping are spiders.
Pretty much what i was thinking before i read the responses. You know, i can't ever remember screaming in my life. Im pretty down to earth, but i dont know. I used to sneak up on my girlfriend before i discover she could bring the roof down with her screams. To say she scared me as much as i scared her would be an understatement. I have never tried it again.
Hahahaha!!!! Never thought of it that way before. But like everyone has said, screaming attracts help, it bares the teeth for attack, etc., which brings our position at the top of the food chain to mind, and the truth that we're only there because we're powerful in numbers and weapons. Bear attacks, shark attacks, you've seen them. A lot of animals out there could easily kill one of us on our own; it's only when we're all together, possibly with weapons, that we earn our top spot.
